With the increasing size of current wind turbines, many of the components of the wind turbines have to be transported individually before being assembled. This is especially the case when bridges or tunnels on the route from the wind turbine factory to the destination restrict the size of the components to be transported. The assembly can take place at the site where the wind turbine is to be erected or at an intermediate place such as a harbour used for shipping the wind turbine components. At such an intermediate place some of the wind turbine components may be preassembled to larger wind turbine sections either before shipping to the destination harbour or to an off-shore wind park or after the individual wind turbine components have been landed at the destination harbour. During assembly one or more cranes are used for handling the large and heavy wind turbine components, especially for lifting and aligning the wind turbine components. However, such equipment is expensive and may not be available at some installation sites such as small harbours.